62 



SAGDA. 



whorl long ; whorls 7 ; alt. 16-18, diam. 17 

 mill. foremaniana. 



cc. Globose ; thin, subtrauslucent, corneous ; 

 base globosely convex, hardly impressed ; 

 columellar fold strong and heavy, spirally 

 entering; basal lamina strong, short, one- 

 fourth whorl long ; whorls 6; alt. 12, diam. 

 12-13 mill. pila. 



ccc. Globose-subconic ; thin but rather solid, 

 translucent ; base very convex, only slightly 

 impressed ; columellar fold a stout nodular 

 callus, somewhat entering; basal lamina 

 strong, about whorl long ; an additional 

 small fold developed betiveen basal and col- 

 umella folds; whorls 6-7 ; alt. 16, diam. 16 

 mill.; alt. 11, diam. 13 mill. triptijcha. 



aa. Basal lamina J to i whorl long, continuous ; base not not- 

 ably convex. 



b. Large, solid and elevated. 



c. Trochoidal ; base not excavated in the 

 middle; no columellar fold; basal lamina 

 deep-seated, about whorl long; whorls 8 ; 

 alt. 24-26, diam. 27-30 mill. alligans. 



cc. Elevated trochoidal ; base deeply excavated 

 in the middle; columellar fold and basal 

 lamina strong within, spirally entering, but 

 sometimes neither is visible from the aper- 

 ture ; whorls 9 ; alt. 25, diam. 27-28 mill. ; 

 alt. 18, diam. 24 mill. jayana. 



bb. Small, thin, depressed. 



c. Depressed-subglobose, thin, subtranslucent 

 greenish-yellow, the surface minutely spic- 

 ulose ; base slightly excavated; columella 

 calloused ; lamina peripheral in position, 

 extending nearly to lip-edge ; whorls 6 ; alt. 

 9, diam. 13 mill. lamellifera. 



cc. Subdiscoidal, thin, translucent, polished; 

 base excavated ; columella calloused ; basal 

 lamina not deep-seated, 3-2 ivhorl long; 

 whorls 6 ; alt. 6], diam. 11 mill. 



osculans. 



